Knitting apparatus



1939. E. TEVENSON 21 I KNITTING APPARATUS Filed April 13, 1958 2Sheets-Sheet 1' .mI INVENTOR 1 I HM/V/rSTEA/E/v 01V; M BY 4 a ATTORNEYAug. 22, 1939. Ii STEVENSQN I 2,170,621

KNITTING APPARATUS Filed April 13, 1938 2 Sheets-sheaf; 2

INVENTOR ATTORNEY Patented Aug. 22, 1939 UNITED STATES PATENT OFFICEHoward Hosiery Company,

Sinking Spring,

Pa., a corporation of Pennsylvania Application April 13, 1938, SerialNo. 201,680

1 Claim.

My invention relates to a new and useful knitted fabric and apparatusfor producing the same 1 5 it drops from the noses of the sinkers anddividers when they are pulled back by the catchbar. This means that thelast knitted loops are held in position by the knockover bits while theneedles move downwardly to pull the thread through the old loops andthen start upwardly again to their initial position to form new loops.In other words, the knockover bits hold the old loops while the newloops are being formed. The knockover bits are carried by a knockoverbar which in turn is actuated through its range of movement by a camand, for different types of fabrics, different cams are used. Inasmuchas the knockover bits have to hold and retain the old loops while thethread is being pulled downwardly by the needles to form a new loop, itis obvious that a tensioning effect is exerted on the old loops inrelation to themselves as well as in relation to the next precedingcourse of loops. It is desirable to apply the maximum tension to the oldloops formed and held by the knockover bits as this tends to produce asmoother, tighter and more uniformly knit fabric, but, due to the rigidlimitation of the movement of the knockover bits according to thecontour and spacing of the actuating cam, it has been found necessary toprovide a relatively large margin or tolerance if excessive waste in themanufacture of the fab ric is to be avoided. Thus, the cam whichactuates the knockover bits is so constructed as to actuate them wellwithin the limits necessary to produce a desirable fabric, since, if theknockover bits were actuated to that maximum desired limit, it has beenfound that excessive breakage of thread and'consequent damage and wasteoccur due to the fragile character of the thread, and the fact that, ifthe knockover bit is moved to the extreme desired position, the pullingon the thread by the needles very frequently breaks the thread. Applyingit specifically, for the purpose of illustration, to the manufacture offullfashioned hosiery, it is possible, without the use of my invention,to produce a fabric which is hard-knit, smooth and uniform inappearance, by simply altering the cam actuating the knockover bits tomove them through a wider range or a longer distance than they areactuated ordinarily, but I have found that by so doing, a considerablenumber of stockings are damaged and wasted. My experience is universalin the trade, and therefore the knockover bits are now so adjusted so asto exert less of a tension on the loops than is really required forproducing the proper fabric. This is in an effort to avoid the excessivewaste referred to. While this does avoid breakage of the thread andWaste, it produces a fabric which is loosely knit and in which the loopsare not uniform in size or appearance. This is due to the fact that thetension applied to the loops is only enough to make uniform some, andperhaps most, but certainly not all of the loops.

While the foregoing difficulties are general in their character andtheir application, it is also to be remembered that the silk which isbeing knit at any given time varies as to its origin, as to itsprocessing and in accordance with the prevailing weather conditions.Thus, a batch of silk made from the cocoons of worms raised in onesection of Japan will not be the same as to its strength, its capacityto absorb moisture, or its flexibility, as another batch of silk whichis produced from worms raised in China or Italy. In other words, onebatch may be very absorbent and hence always flexible, whereas, anotherbatch may be relatively non-absorbent so that, even when passed througha humidfying device attached to a knitting machine, it shakes off thewater and retains a hard, brittle, or fragile character. Similarly, inthe processing of silk which is known as throwing, the treatment, evenof the same type of silk, may not be quite uniform with the result thatthe finished thread is also not unifiorm. When it is remembered that themanufacturer of silk fabric buys silk by the bale and cannot determineits origin nor its uniformity, it will be seen that there will be greatvariation in the tension as well as friction developed in connectionwith lengths of thread derived from the same bale or batch. To take careof this situation the manufacturer makes a test of a batch of silkbefore beginning the knitting operation and adjusts the machineaccordingly. This, however, is practically useless because, if the testwas conducted on the end of a thread which happens to be flexible andmoisture-absorbent, and the machine is tensioned accordingly, it ispossible,

before the same bobbin or cone of silk is exhausted, to come across alength of thread that is hard and non-absorbent and the relatively greattensioning of the machine when adjusted to the pliable and absorbentthread would now result in breakage. I can assert this from actualexperience over many years in the manufacture of fullhashioned hosiery.It is of course very wasteful and most impractical to have to stop themachines and readjust them whenever breakage occurs for the reason thatthe hard section of the thread which necessitated reduction of thetension may be followed by a soft, absorbent section of thread which,unless the machine is again readjusted, would result in a poor grade offabric. Furthermore, even if the thread were assumed to be perfectlyuniform in its flexibility, tension and moisture-absorbent qualities(which is only for the sake of argument as such a thread does not exist)it will be seen that with the change of temperature and humidity in theatmosphere, which despite all mechanical adjustments neverthelessoccurs, the quality of the thread will vary accordingly. Thus, if themachines are adjusted in the morning of a given day to a certain degreeof tension, and in the morning the weather was cold, crisp and dry, itmay be necessary to make another adjustment if, with a sudden change,the weather becomes rainy and damp, or vice versa. Also, it may benecessary to knit a finer or a heavier thread on the same machine tofill different orders and again it would be necessary to readjust thetension of the machine as to the knockover bits and the othercooperating parts which represents loss of time and expense.

From the foregoing I have concluded that the only way to remedy thisvery serious condition which is responsible for a relatively largepercentage of the cost of stockings is to provide a knitting machinewith what may, for the purpose of definition, be described as a shockabsorber adapted to act on the knitting parts of the machine, and I havefound it most convenient as a matter of practice to apply this shockabsorber which is in the nature of a yielding tension to the knockoverbits of the machine thereby cushioning the knitting operation and thusenabling me to apply sufiicient tension which would insure the properand smooth and uniform knitting of fabric when the softest, mostpliable, and strongest thread is being used, but which yielding tensionwould give when a relatively, hard, non-absorbent, non-flexible, threadis used thus insuring a perfect fabric and entirely eliminating alldamage or breakage which is. attributable to any or all of the causesabove re ferred to or their ramifications.

After extensive research I have produced an extremely simple attachmentwhich can be ap" plied to standard machinery at negligible cost of timeor material, and which, without increasing the breakage and perhaps evendecreasing the present rate of breakage and waste, will enable a machineto produce a hard-knit, smooth and uniform fabric which it hasheretofore been impossible to produce except at great cost due to thebreakage and damage risk, which was considerable.

My invention will be more clearly understood from the followingspecification and the accompanying drawings in which:

Fig. 1 represents a fragmentary and diagrammatic view, partly invertical elevation and partly in section, of certain parts of a flatknitting machine showing my invention.

Fig. 2 represents a right hand elevation of Fig. 1 certain parts beingomitted.

Fig. 3 represents a perspective View of the at tachment embodying myinvention shown detached, the same being the type applied to the righthand end of the knitting machine.

Fig. 4 represents, on an enlarged scale, the the central portion of Fig.1 showing the parts in a different position and more clearlyillustrating my invention.

Fig. 5 represents a view on line 55 of Fig. 4.

Fig. 6 represents diagrammatically, and on an enlarged scale, but onlyin line drawing, the appearance of the fabric that would be produced bya fiat knitting machine without the use of my invention, showingirregularities in the formation of the loops.

Fig. 7 represents diagrammatically the same defects shown in Fig. 6expressed in terms of loops or chain stitches instead of line drawing.

Fig. 8 is a view similar to Fig. 6 illustrating how the appearance ofthe fabric is improved by the use of my invention.

Fig. 9 is a view similar to Fig. '7 translating the uniformity ofappearance illustrated in Fig. 8 and expressing it in terms of loops orchain stitches.

Referring to the drawings in which like refer ence characters indicatelike parts, and more particularly to Fig. 1 in which I havefragmentarily and diagrammatically illustrated the minimum number ofparts of a conventional machine which is necessary for illustrating myinvention, Ili designates a rocker arm which is carried by the shaft l2,and carries the roller l4 adapted to ride on the cam l6 which is rotatedby the shaft [8. 2D designates an arm having the hook or stop 22 forlimiting the movement of the rocker arm ill in the direction of thearrow 2 1 against the action of the spring 25 which exerts a con stantpressure on the rocker arm in the direction of the arrow 24. Pivoted tothe rocker arm at is the link 28 which in turn is pivoted at 30 to thearm 32 which is secured to the shaft 34 by the set screw 36 or the like.40 designates another rocker arm which is secured to the shaft 34 by theset screw 42 or the like, and which is provided with the head or sleeve44 which is secured to the stub shaft 46 as at 48. 50 designates a linkwhich has an opening 52 in one end thereof, through which the shaft 46passes, and another opening 54 in the other end thereof in which isseated the pin 56. On the pin 56 is pivotally mounted the arm 58 whichin turn is rigidly secured at 6!? to the knockover bar 62 which carriesthe knockover bits 64. As the cam 16 rotates, so that the roller H!rides on the high portion thereof, the rocker arm i0 is moved in thedirection of the arrow 68. This moves the arm 32 in the direction of thearrow 68 and the arm 40 in the direction of the arrow 10 to push thelink 59 in the direction of the arrow 12. When the link 59 is moved inthe direction of the arrow 12, the arm 58 is moved in the direction ofthe arrow Hi and this results in lifting the knockover bits 6 in thedirection of the arrow 16. The movement of the knockover bits in thedirection of the arrow 16 exerts a tensioning effect on the loops 18which have just dropped over the knockover bits in the usual manner (notshown). The loops 18 are held on the knockover bits while the needles8!! are moving downwardly. Except for the shape of the opening 52 beingoval, whereas in the .conventional machine it is round, the same as theopening 54, the parts heretofore described, together with theirfunctions, form no part of the invention. In order to apply suiiicienttension to produce proper knitting, but to have this tension,nevertheless, a yielding one so as to give under excessive pressurerather than'break the thread, I have elongated the opening 52, in whichthe actuating shaft 46 is disposed, and I have provided the arm with theleg 84 which is engaged by a spring 86 the other end of which isanchored to the pin 88 which in turn is carried by the collar 98 orother suitable point on the frame. During normal operation the spring 86serves to retain the rear edge 92 of the elongated opening 52 againstthe stub shaft 46. With the use of the arm 50, the spring 86 and theelongated opening 52, I am enabled to use a higher cam l6 or otherwiseadjust the movement so as to increase the stroke of the rocker arm ID,the link 28 and the arms 32 and 46, and therefore raise the knockoverbits somewhat higher or increase the length of their stroke so as toinsure the desired and effective tension on the loops 18, but, at thesame time, avoid all danger of breakage, since, as shown in Fig. 4, ifthe tension against the knockover bits 64 reaches a certain point whichis in excess of the tension of the spring 86, which in turn is adjustedwith relation to the tensile strength of the thread being used, thedownward pressure of the loop 18 on the knockover bit 64 moves the arms58 and 58 in the direction of the arrow 96. This releases the stub shaft46 from engagement with the rear end 92 of the elongated opening 52 sothat the shaft 46 may assume the position shown in Fig. 4, not becausethe shaft 46 has been moved, but because the arm 50 has been moved (fromleft to right in Fig. 4) relative to the shaft 46.

In Figs. 6 and '7 I have illustrated the fabric produced in actualpractice by a standard knit-' ting machine without the use of myattachment, and I have diagrammatically shown the non-uniform, irregularor misshaped stitches 98 which are either longer or shorter than theyshould be, or which are otherwise distorted. In Figs. 8 and 9 I haveillustrated a fabric produced by the same standard machine after myattachment had been applied as shown, and in which the stitches I88 areexactly uniform.

My invention, therefore, consists in providing the knockover bits withcertain play or clearance which in turn enables me to exert sufficienttensioning on the stitches of a fabric to produce the desireduniformity, while, at the same time, completely eliminating the dangerof breakage and consequent waste.

Thus, While the shaft 46 is in contact with the rear edge 92 of theopening 52, the arm 58 will be actuated to the limit of the stroke, towhich the cam l6 and other parts are adjusted, thus raising theknockover bits to the extreme limit necessary for proper tensioning ofthe loops, but, if the opening 52 were. round-the same as the shaft46-and if there were no spring 86, such movement would be uniform andthe knockover bits would be raised to their extreme position whetherthey be needed or not, and regardless of whether or not the amount oftension thus exerted would cause the thread to break. By making theopening 52 elongated, and by providing the spring 86, I causethe partsto move to the extreme desired limit, but at the same time such partswill be moved with a force only equal to the tension of the 'spring 86and not the inexorable force which would be exerted by the rigid actionof the cam l6 on the roller I4. It is thus clear that while, as long asthe loops carried by the knockover bits are loose, and until they aresufliciently tightened,

the knockover bits will be pushed upwardly by the knockover mechanismplus the tension of the spring 86, and that, as soon as the loops havebeen suificiently tightened, the spring 86 yields and the arms 50 and 58will stop their movement, or perhaps retrograde slightly, and in thisway avoid breakage of the thread which will be inevitable in any attemptto tighten the loops by the knockover bits without the provision of theplay afforded by the opening 52 and the tensioning action of the spring86,

While I have described my invention as applied to the type of fabric ofwhich full-fashioned hosiery is made, due to the fact that my inventionwas first conceived in connection therewith, it is to be understood thatthe invention is applicable to the knitting of any other kind of fabricand to the tensioning of any other type of stitch in connection withwhich it may be necessary. Also, while I have described the mechanicalconstruction, the operation of the attachment, and shown the improvedfabric it produces, it is obvious that my invention is not restrictedonly to the mechanical apparatus but also embodies the novel method ofknitting a fabric in that the loops retained and actuated into positionby the knockover bits are acted upon by a yielding tensioning for theproper formation of the stitches and at the same time to providetensioned tolerance which avoids breakage and waste.

With reference to Fig. 3 wherein I have shown the attachment as it wouldbe used on the righthand end of the knitting machine, it is to beunderstood that an attachment, which would be the reverse of Fig. 3, isused in connection with the left-hand end of the machine. Also, while Ihave shown the elongated hole 52 as being formed in the end of the arm50 nearest to the arm 84, it is to be understood that the hole 52 can bemade round and that the opening 54 in the opposite end of the arm 50 canbe made elongated to afford the necessary play without departing fromthe scope of my invention.

While I have shown the yielding tension or cushioning effect asincorporated in the arm 56 by means of the elongated hole 52 and thespring 86, it is to be understood that my invention being broadlydirected to the idea of cushioning or yieldably tensioning the knockoverbit mechanism can be applied to any of the other actuating parts of theknockover bit actuating mechanism proper. For instance, instead ofrigidly securing the arm 58 to the knockover bar 62 at 66 I can make theconnection 60 a pivotal one and apply a tension spring to the knockoverbar 62 directly, in the same manner that the spring 86 is connected tothe arm 50, and achieve the same results without the necessity of theplay afforded by the elongated hole 52.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

The combination with a knockover bit mechanism of a fiat knittingmachine and the actuating mechanism thereof, of means for yieldably gagea pin at the lower end of an arm, which arm supports and engages theknockover' bit shaft, and having an elongated opening at the other endthereof adapted to engage a round cross-sectional shaft forming part ofthe knockover bit actuating mechanism, a pendant leg formed at the endof said link adjacent said elongated opening, and a spring having oneend thereof connected to said leg and the other end thereof connected tothe frame of the knitting machine for constantly urging said link in thedirection of said pin, whereby said link is enabled to move away fromsaid pin and against the tension of said spring when the tension of theknockover bit mechanism has reached a predetermined limit.

FRANK STEVENSON.

